intermediate alto sax question

Hey, I've been playing sax for 16 years myself. I'm not going to suggest you go out and buy a selmer or yanigasawa. What I would say is that Yamaha make some of the best student model horns. You should be able to pick one up second hand for around your price point. Other than Yamaha I'd suggest Antigua. I play one of their sopranos and it is fantastic! Other brands that may be of interest (I haven't played any of these myself so others may be able to give more detail) would be: cannonball, Trevor James, Jupiter.
You will get better bang for your buck if you hunt out a second hand horn in good condition. There tends to be a lot of preowned horns on the market simply cause their owners just don't have the time to learn them. So a lot of nearly new ones out there.

What was the model of Antigua? Like i said earlier, i have one of their sopranos and it really is a great horn. They do have about three different levels of alto from what I can see. I've seen the pro one in action and it sounds fantastic (there are a fair few you tube videos if people playing then. In particular some Russian player who was a total monster! I'll see if I can find that vid). But I doubt you would get that for less than 1k.

I have heard that Bauhaus are decent Asian horns too (think I read it on Pete Thomas' site)

One other place for you to research is forum.saxontheweb.net/forum.php

Tonnes and tonnes of discussions and reviews on nearly every make of horn you could imagine. As long as the money is still in your pocket you can afford to take your time and research each.

Ultimately the best advice is to play these each horn where possible. You will have your own preferences that may be different to mine or anyone else's. You will know when you have found the right horn.